The invention relates to an apparatus reverse stranding, for the manufacturing of conductors, such as filaments, conductor elements, bundles of conductors, optical fibres or equivalent, said apparatus comprising a stationary distributor means disposed at the upstream end for the conductors to be twisted, a twisting means rotatable in different directions and disposed at the downstream end for the conductors to be twisted, and peripheral tubes disposed between the distributor means and twisting means, being twistable recurrently about their longitudinal axes in opposite directions and peripherally surrounding a central tube, the central tube and peripheral tubes being pressed against each other at least during the step of twisting the conductors, and the conductors to be twisted being adapted to pass through at least the peripheral tubes. The invention further relates to a method in connection with reverse stranding, comprising drawing conductors, such as filaments, conductor elements, bundles of conductors, optical fibres and the like, from a distributor means into a nozzle or the like through peripheral tubes circumferentially surrounding a central tube and being twistable about the central tube recurrently in opposite directions, as well as a method in connection with the stranding of optical fibres, comprising feeding fibres from a distributor means into a nozzle or the like through peripheral tubes surrounding a central tube, transporting a core member provided with grooves through the central tube, and guiding the fibres by means of the peripheral tubes into the grooves in the core member.
Many different kinds of apparatus and methods as presented above are known in the cable industry. The apparatus and method disclosed in U.S. Pat. No. 4,974,408 may be mentioned as an example of the known solutions. The solution disclosed in U.S. Pat. No. 4,974,408 operates completely faultlessly in most circumstances. However, in some circumstances it has been found that the friction characteristics between the conductors and the inner surfaces of the peripheral tubes are not optimal. Furthermore, specifically optical cables have presented problems in the bending and heat expansion of the cables, which have resulted in an increase in the damping of the cable.